The enormous development of street and highway traffic results in a steadily growing number of traffic accidents. These accidents bring about great material losses and, first of all, are incommensurable in relation to human losses; loss of life, or permanent invalidism. The safety of traffic on the highways and streets depends to a considerable degree on the fact that a driver will succeed in a definite traffic situation to react in a proper way, and sufficiently fast. The psychology of street and highway traffic attempts to explain these problems. The subject of its investigation is a detailed analysis of the driver's work, to establish psycho-physiological functions indispensable for its safe execution. The driver's work has a specific character. In addition to some acquired information, training and possession of driving competence, the driver is also required to possess a particular psycho-physiological competence, considering the dynamics of the driven vehicle, and the human life and health hazards connected with it.
Among the great number of drivers traveling on the streets and highways there are some, who often do not realize that they have certain psycho-physiological deficiencies. This is why a necessity arises for controlling psycho-physiological characteristics of drivers before their licensing and during their execution of work as concerns changes or disappearance of psycho-physiological competence.
The proper evaluation of psycho-physiological characteristics of a driver can be made only by using certain types of testing apparatus, specialized and adapted for this aim. One such apparatus to serve such aims is my present invention. It can be used for studying the precision of motions connected with the tremor of hands which appears with illnesses of the nervous system, alcoholism, and old age. This device has been already successfully tested in several cases for determining the presence and degree of such afflictions.